class PlaceBlock

final class PlaceBlock implements ConfigActionPluginInterface, ContainerFactoryPluginInterface {
    public function __construct(ConfigActionPluginInterface $createAction, string $whichTheme, ConfigFactoryInterface $configFactory, ConfigEntityStorageInterface $blockStorage) {
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($container->get('plugin.manager.config_action')
            ->createInstance('entity_create:createIfNotExists'), $plugin_definition['which_theme'], $container->get(ConfigFactoryInterface::class), $container->get(EntityTypeManagerInterface::class)
            ->getStorage('block'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function apply(string $configName, mixed $value) : void {
        assert(is_array($value));
        $theme = $this->configFactory
            ->get('system.theme')
            ->get($this->whichTheme);
        $value['theme'] = $theme;
        if (array_key_exists('region', $value) && is_array($value['region'])) {
            // Since the recipe author might not know ahead of time what theme the
            // block is in, they should supply a map whose keys are theme names and
            // values are region names, so we know where to place this block. If the
            // target theme is not in the map, they should supply the name of a
            // fallback region. If all that fails, give up with an exception.
            $value['region'] = $value['region'][$theme] ?? $value['default_region'] ?? throw new ConfigActionException("Cannot determine which region to place this block into, because no default region was provided.");
        }
        // Allow the recipe author to position the block in the region without
        // needing to know exact weights.
        if (array_key_exists('position', $value)) {
            $blocks = $this->blockStorage
                ->loadByProperties([
                'theme' => $theme,
                'region' => $value['region'],
            ]);
            // Sort the blocks by weight. Don't use \Drupal\block\Entity\Block::sort()
            // here because it seems to be intended to sort blocks in the UI, where
            // we really just want to get the weights right in this situation.
            uasort($blocks, fn(BlockInterface $a, BlockInterface $b) => $a->getWeight() <=> $b->getWeight());
            $value['weight'] = match ($value['position']) {    'first' => reset($blocks)->getWeight() - 1,
                'last' => end($blocks)->getWeight() + 1,
            
            };
        }
        // Remove values that are not valid properties of block entities.
        unset($value['position'], $value['default_region']);
        // Ensure a weight is set by default.
        $value += [
            'weight' => 0,
        ];
        $this->createAction
            ->apply($configName, $value);
    }

}